Draft regulator



Dec. '1, 1925. 1,564,023

I D. J. SCANLAN DRAFT REGULATOR Dan/1.4 J jaw/7hr;

Patented Dec. 1, 1925.

UNITED STAT-Es DANIEL J. SGANLAN, OF ST. LOUIS, MISSOURI.

DRAFT REGULATOR.

Application filed. October 2?, Serial No. 671,081.

To all whom it may concern:

Be it known that I, DANIEL J. SCANLAN, a citizen of the United States, residing at the city of St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Draft Regulators, of which the following is a specification.

One of the objects of this invention is to control automatically the combustion within a furnace or the like.

This invention is particularly applicable to h0t-air furnaces and another object is to regulate automatically the supply of cold air into the hot-air chamber of a hot-air furnace, while simultaneously regulating the combustion.

A further object is to provide means for manually adjusting the automatic combustion-controlling means, whereby a subnormal temperature may be maintained at certain times as desired, as for instance, at night for safety purposes. These manual adjustments do not, however, affect the normal operation of the means for controlling the supply of cold air into the hot-air chamber.

Other objects and advantages will be ap-.

parent as the description proceeds.

In the accompanying drawings forming part of this specification, in which like numbers of reference denote like parts wherever they occur,

Figure 1 is a fragmentary front elevation of a hot-air furnace to which this invention has been applied;

Figure 2 is a side elevation of the same; and

Figure 3 is a transverse sectional view through a hot-air pipe and showing a thermostat located therein and with its external connections.

' A thermostat 1 is preferably located in one of the hot-air pipes 2,- and for that purpose suitable means of support must be pro vided, such, for instance, as the hanger 3 suitably attached at its ends 4 to the interior of the said pipe 2 and preferably supported:

by any suitable support 5.

The thermostat 1 is a hollow diaphragm and contains a liquid, preferably water, that is readily expansible or contractible with the increase or decrease of heat of the adjacent hot air flowing through the pipe 2.

This diaphragm 1 is preferably made of copper or other suitable material arranged in pleats 6, so that when in its contracted sion within it of its liquid contents.

form its longitudinal extension is materially less than when it is distendedby the expanlVhen distended, thepleats 6 may be almost ironed out, so to speak; but in its contracted form the pleats lie uponeach. other. This alternate contraction and distention resembles an accordion. y

. Diaphragm or thermostat 1 is held in place upon hanger 3 by lugs 7 or other suitable means. A tubular guide 8 is secured to a rod'9, upon one end of which is preferably attached a plate 10 in inner contact with or attached to some part of the diaphragm 1. By this means, when. diaphragm 1 expands, plate 10 and rod 9 are pressed outward to the furthermost position shown in full lines in Figure 3, rod 8 moving through opening 11 in pipe 2; but when diaphragm -1 contracts gravity and spring 12 cause the lowering of rod 8 and plate 10to the inner dotted position. Upon the other end of rod 9 is mounted a block 13, which in Figure 3 is shown in full-line and dotted-line posi tions, according to whether the diaphragm 1' is expanded or contracted.

- A lever 14 is pivoted at 15 to a bracket 16 preferably mounted upon the outside of pipe 2. Lever 14 extends in one direction in juxtaposition to block 13 and has secured thereto a pin 17 which engages. a horizontal slot 18 in the block 13., Further towards the end of this extension of'the lever 14 are a series of apertures 19, for receiving a hook 20 of a weight 21. The other end of lever 14;isprovided with a hook or finger 22, adapted to fit in any one of the holes 23 in regulation plate 24. That moment of lever 14 due to the weight 21 may be varied by changing the book 20 from one to another of the holes 19, thereby securing the most favorable position for the weight 21 that is necessary to properly balance the weight of the regulation plate 24 and its associated parts and assist the spring 12 in contract- 7 ing the diaphragm 1.

The lower end 25 of regulation plate 24 tion plate 24 isv connected by a chain 32 to the check-draft door 33, pivoted'at 34 to the chimney pipe 35.

Chain 32 is supported by rolls 36 in hangers" '37, which are secured to the ceiling 38.

A chain 39, connected at to thelever a 14, passes over rolls 41, in hangers 42, se

cured to the ceiling 38, and connects at its other end 43 with lever 44, which operates damper 45 pivoted at 46in cold' -air intakepipe 47, which leads to the exterior of the building.

The chains 26 and 32 are of such respective lengths as to be just taut when draftdoor 27 and checlcdraftdoor 33 are simul taneously in closed positions, as shown in Figure 2; and during normal operation this condition obtains with the regulation plate 24 at approximately the middle of its stroke, and with lever 14 substantially horizontal, and connected. to the middle of plate 24, as shown in full lines in Figure 2, and with the thermostat 1 atthc middle of its stroke. In this. position, also, cold-air damper 45 1s openhalf-way, the weight oflever 44 being sufficient to overcome the friction encountered in operating the damper. 45, and to keep the-chain 39 taut, as mchcated 1n full lines in Figure 2. The weight of thedoors 27 and 33 is sutficient to close them whenever permitted by the slackening of their re spective chains. 26 and 32.

The mode of operation ofthis device will now be described.

When the diaphragm 1 expands, the rod 8 is pushedoutwardly and likewise the block 13. This causes lever 14 to rock on pivot 15, whereby. the end bearing. hook 22 is depressed, thus allowing plate 24 andchain 26 to descend. lVhen the plate 24 has descended through a certain portion of 1ts stroke, the draft-door 27 is brought to its closedposition, as shown in Figure 2, thus cutting off the supply of air to the fire.- I n thisposition the check-draft door 33 is still closed. This is important, as the check draft door must not be opened until the supply of. air to the fire has been cut off. In. the meanwhile, damper 45hasopened halfsvvay from its closed position by the pull on the chain 39, admittinga limited supply of cold air into the hot-air chamber. Asthe diaphragm 1 contlnues to expand, chain 26 becomes slack, and the check-draft door 33 is opened by they pull on thechain 32.; Simultaneously damper has been opened. completely by the pull of the chain 39v thereon. This. action simultaneously checks the draft at the chimney, and, also, admits more cold air from outdoors through pipe147 intothe furnace .30. Allof the-foregoing operations tend to retard combustion and cool thefurnace. a

When the furnace cools, the temperature decreases in the pipe 2' and this results in the contraction of the diaphragm 1'. results inthelowering. of rod 8 and block 13, ,whereby lever 14 rocks u-ppn pivot 15, automatically elevating'hookf 22 and plate 24, and partly closing the damper45and entirely closing the check-draft door '33 and taking the slack out of chain 26 As the diaphragm 1 continues to contract, plate 24 is elevated still more, whereby draft-door 27 is automatically opened by the rising chain 26, thus re-establishing the draft through the fire; and chain 39 recedes toward the damper 45, allowing the weight of the lever 44 to entirely close the damper 45. The furnace 30 is thus caused to give forth more heat, which eventually, when needed again, eX- pands thermostat 1, and in succession performs a repetition of the closing of the draft-door 27 and the opening of checkdraft door and damper 45.

So far the description of the operation has reference only to the normal functioningof this device. It may be desirable for certain reasons to cause the device to function abnormally at times. For instance, at night, it is preferable to let the fire burn slowly, for purposes of safety as well as forthe purpose of lowering the temperature. To accomplish this,it is merely necessary to insert the hook 22 of lever 14' into the highest of the holes 23, so that the regulatingplate 24 is lowered from its normal position relatively to lever. 14, so much so that chain, 26 can never become tight enough to open the draft-door 27, irrespective of theoperation of the thermostat-1. However, the functioning of check-draft door is not prevented under these circumstances, but its-action is advancedin time so that it begins to check the draft before the furnace has acquired the heat which is necessary to actuate the; door 33 under normal conditions. Also, because of the lowering of plate 24, door 33'will openfurther than under normal conditions if the furnace becomes very hot. Chain 39 being, directly connected to the lever 14, the normal regulationof'the supply ofcold air by the damper 45 is not afi'ected by: adjusting, the

plate 24- relatively, to the lever-l4, so that a given amount of cold air is always admitted to a given temperature, under both normal and abnormal settings of the plate 24 relativelyto the lever 14. p

Having thus described this invention, I hereby, reserve the benefit of all changes in form, arrangement, order, or use'of parts, as it is evident that many minor changes may be made therein without departing from the'spirit of this invention or the scope. of i the following claims.

I claim 1. Thecombination liot-air furnace provided with a.;l1otair pipe, of, a thermostat located insaid hot-air pipe in spaced relation to the body oftlie'furnace, means directlyioperated by the said thermostat for controlling the supply-of cold air to the air-heatingchamber of the said furnace, and separate means adjustable relati'vely to the said thermostat and operated thereby for controlling the draft through the fire.

2. The combination with a hot-air furnace provided with a hot-air pipe, of a thermostat located in said hot-air pipe in spaced relation to the body of the furnace, a lever actuated thereby, means connected to the said lever for controlling the supply of cold air to the air-heating chamber of the said furnace, a member adjustably connected to the said lever, and means actuated by the said member for controlling the draft through the fire.

3. The combination With a hot-air furnace provided with a hot-air pipe, of a thermostat located in said hot-air pipe in spaced relation to the body of the furnace, a lever actuated thereby, a flexible member connecting the said lever with the damper controlling the supply of air to the airheating chamber of the said furnace, a member adjustably connected to the said lever, and a second flexible member connecting the said adjustable member with the draftdoor of the furnace.

4E. The combination with a hot-air furnace provided with a hotair pipe, of a thermostat located in said hot-air pipe in spaced relation to the body of the furnace, a lever actuated thereby, a flexible member connecting the said lever with the damper controlling the supply of air to the airheating chamber of the said furnace, a member adjustably connected to the said lever, and a second flexible member connecting the said adjustable member with the checkdraft door of the furnace.

The combination with a hot-air furnace )rovided with a hot-air pipe, of a thermostat located in said hot-air pipe in spaced relation to the body of the furnace, a lever actuated thereby, a flexible member connecting the said lever with the damper controlling the supply of air to the air-heating chamber of the said furnace, a member adjustably connected to the said lever, a second flexible member connecting the said adjustable member with the draft-door of the furnace, and a third flexible member connecting the said adjustable member with the check-draft door of the furnace.

6. The combination with a hot-air furnace provided with a hot-air pipe, of a thermostat located in said hot-air pipe in spaced relation to the body of the furnace, a lever actuated thereby, a chain connecting the said lever with the damper controlling the supply of air to the air-heating chamber of the said furnace, a chain connecting the draft-door with the check-draft door and a plate borne by the said chain and having a plurality of holes for engaging the end of the said lever.

In testimony whereof I hereunto aflix my signature.

DANIEL J. SCANLAN. 

